The present invention relates to an apparatus and a method for thermalizing (raising of dough, hot food holding, poaching, roasting, baking, steaming, or otherwise heating or maintaining the temperature of food) in an oven, and more specifically, thermalizing the food in a manner which accurately and predictably controls the doneness temperature of the food item as well as the degree of browning or texturing of the food item.
Traditional ovens characteristically utilize a dry heat system. The limitations of this equipment have led users to develop alternate cooking techniques, such as papillote cooking (bag cooking) in an effort to have some control over the parameters which actually affect the quality of the end product. Winston Industries has manufactured ovens or thermalizers having water reservoirs (evaporators), in which the temperature of water in the evaporator was controlled, and these ovens or thermalizers have provided a much improved ability to control the quality of the food.
However, it has been found that controlling the temperature of the water in the evaporator is not enough to provide the most accurate control of the temperature and moisture of the food itself. Since the oven or thermalizer is vented, the conditions inside the food chamber are not the same as the conditions at the evaporator.
The present invention provides a wet bulb temperature sensor inside the food chamber, which much more closely represents the condition of the food being prepared. This wet bulb sensor preferably is located near the oven vent and preferably is kept wet by the condensate of the vapor leaving the food chamber through the vent, and thus senses the same conditions that the food is being subjected to.
In a preferred embodiment, a temperature sensor projects into the vent, which has a perforated funnel shape, and a wire spring that is wrapped around the bottom portion of the temperature sensor catches the condensate in the funnel-shaped vent area and, through capillary action, created by the small gap between the wire and the bulb, this condensate coats the surface of the bottom portion of the temperature sensor, making it a wet bulb temperature sensor.
The control system then controls the wet bulb temperature inside the food chamber by controlling a heater inside the evaporator (a wet heater), and it controls the difference between the dry bulb temperature and the wet bulb temperature by controlling a heater that heats the air in the food chamber (a dry heater).
The food itself is like a wet bulb sensor, since it has a moist outer surface and is sensing the conditions inside the oven, so the wet bulb sensor closely approximates the conditions of the food. By being able to control the wet bulb temperature and the difference between the wet bulb temperature and the dry bulb temperature inside the food chamber, the cook can control the temperature and the browning or texturing of the food.
Thus, this thermalizer or oven gives the cook a superior ability to control the quality of food and to reproduce that quality on a regular basis.